System and Method for Auto-Detection of WLAN Packets using STF

ABSTRACT

A system and method of auto-detection of WLAN packets includes selecting a first Golay sequence from a first pair of Golay complementary sequences associated with first packet type, each Golay sequence of the first pair of Golay complementary sequences being zero correlation zone (ZCZ) sequences with each Golay sequence of a second pair of Golay complementary sequences associated with a second packet type, and transmitting a wireless packet carrying a short training field (STF) that includes one or more instances of the first Golay sequence.

This patent application claims priority to U.S. Provisional ApplicationNo. 62/115,445, filed on Feb. 12, 2015, and entitled “Method andApparatus for Auto-Detection of WLAN Packets,” and U.S. ProvisionalApplication No. 62/219,794, filed on Sep. 17, 2015, and entitled “Systemand Method for Auto-Detection of 60 GHz WLAN Packets in STF,” both ofwhich are hereby incorporated herein by reference.

TECHNICAL FIELD

The present invention relates generally to wireless networks, and inparticular embodiments, to techniques and mechanisms for auto-detectionof wireless local area network (WLAN) packets.

BACKGROUND

With the increasing demands of high-definition (HD) displays and otherapplications, and with the widespread usage of smart phones and tablets,next generation WLANs capable of transmission at higher data rates areneeded. IEEE 802.11ad is a WLAN technique that operates in the globallyunlicensed 60 GHz band, e.g., 57-66 GHz. Next generation 60 GHz WLANs(NG60), capable of even higher performance than 802.11ad, have beenproposed. Although such networks may be capable of higher performance,there is also a need for them to be compatible with current 802.11addevices.

SUMMARY OF THE INVENTION

Technical advantages are generally achieved by embodiments of thisdisclosure, which describe auto-detection of WLAN packets.

In accordance with an embodiment, a method is provided. The methodincludes receiving a wireless packet in a 60 GHz frequency bandcomprising a short training field (STF), determining a first quantity ofcross-correlation peaks between the STF and a first preamble componentsequence, and a second quantity of cross-correlation peaks between theSTF and a second preamble component sequence, the first quantity being afirst threshold or the second quantity being a second threshold for afirst packet type, the first quantity being the second threshold or thesecond quantity being the first threshold for a second packet type, anddetermining that the wireless packet is the second packet type when thefirst quantity of cross-correlation peaks equals the second threshold orthe second quantity of cross-correlation peaks equals the firstthreshold.

In some embodiments, the first threshold is forty-eight and the secondthreshold is sixteen. In some embodiments, the first packet type is anInstitute of Electrical and Electronics Engineers (IEEE) 802.11ad packettype, and the second packet type is an IEEE 802.11ay packet type. Insome embodiments, the first preamble component sequence is Ga₁₂₈ and thesecond preamble component sequence is Gb₁₂₈.

In accordance with an embodiment, a method is provided. The methodincludes transmitting in a 60 GHz frequency band a wireless packetcomprising a short training field (STF), a header, a payload, and atraining field, the STF producing a first quantity of cross-correlationpeaks when correlated with a first preamble component sequence, the STFproducing a second quantity of cross-correlation peaks when correlatedwith a second preamble component sequence, the first quantity being afirst threshold or the second quantity being a second threshold for afirst packet type, the first quantity being the second threshold or thesecond quantity being the first threshold for a second packet type.

In some embodiments, the first threshold is forty-eight and the secondthreshold is sixteen. In some embodiments, the first packet type is anInstitute of Electrical and Electronics Engineers (IEEE) 802.11ad packettype, and the second packet type is an IEEE 802.11ay packet type. Insome embodiments, the first preamble component sequence is Gb₁₂₈ and thesecond preamble component sequence is Ga₁₂₈.

In accordance with an embodiment, a method is provided. The methodincludes receiving a wireless packet in a 60 GHz frequency bandcomprising a short training field (STF), determining a first quantity ofcross-correlation peaks between the STF and a first preamble componentsequence, and a second quantity of cross-correlation peaks between theSTF and a second preamble component sequence, the first quantity being afirst threshold or the second quantity being a second threshold for afirst packet type, removing a phase shift from the STF to produce aphase shifted STF, determining a third quantity of cross-correlationpeaks between the phase shifted STF and the first preamble componentsequence, and a fourth quantity of cross-correlation peaks between thephase shifted STF and the second preamble component sequence, anddetermining that the wireless packet is a second packet type when thethird quantity equals the first threshold or the fourth quantity equalsthe second threshold.

In some embodiments, the first packet type is an Institute of Electricaland Electronics Engineers (IEEE) 802.11ad packet type, and the secondpacket type is an IEEE 802.11ay packet type. In some embodiments,removing the phase shift from the STF comprises applying a linear phaserotation other than

$^{j\; \pi \frac{n}{2}}$

to the STF. In some embodiments, removing the phase shift from the STFcomprises applying a block rotation to the STF.

In accordance with an embodiment, a method is provided. The methodincludes adding a phase shift to a short training field (STF) to producea phase shifted STF, and transmitting in a 60 GHz frequency band awireless packet comprising the phase shifted STF, a header, a payload,and a training field, the phase shifted STF producing a first quantityof cross-correlation peaks when correlated with a first preamblecomponent sequence and a second quantity of cross-correlation peaks whencorrelated with a second preamble component sequence, the phase shiftedSTF producing a third quantity of cross-correlation peaks whencorrelated with the first preamble component sequence and a fourthquantity of cross-correlation peaks when correlated with the secondpreamble component sequence after the phase shift is removed from thephase shifted STF, the first quantity being a first threshold or thesecond quantity being a second threshold for a first packet type, thethird quantity being the first threshold or the fourth quantity beingthe second threshold for a second packet type.

In some embodiments, the first packet type is an Institute of Electricaland Electronics Engineers (IEEE) 802.11ad packet type, and the secondpacket type is an IEEE 802.11ay packet type. In some embodiments, addingthe phase shift to the STF comprises applying a linear phase rotationother than

$^{j\; \pi \frac{n}{2}}$

to the STF. In some embodiments, adding the phase shift to the STFcomprises applying a block rotation to the STF.

In accordance with an embodiment, a method is provided. The methodincludes receiving a wireless packet comprising a short training field(STF), determining cross-correlations between the STF and a firstpreamble component sequence from a first set of preamble componentsequences associated with a first packet type and between the STF and asecond preamble component sequence from a second set of preamblecomponent sequences associated with a second packet type, the firstpreamble component sequence and the second preamble component sequencehaving a zero correlation zone (ZCZ) property, and determining that thewireless packet is the second packet type when there is a greatercorrelation between the STF and the second preamble component sequencethan between the STF and the first preamble component sequence.

In some embodiments, the first packet type is an Institute of Electricaland Electronics Engineers (IEEE) 802.11ad packet type, and the secondpacket type is an IEEE 802.11ay packet type. In some embodiments, theZCZ property is a ZCZ of at least 64 symbol time slots in width. In someembodiments, the first set of preamble component sequences comprisepreamble component sequences Ga₁₂₈ and Gb₁₂₈. In some embodiments, thesecond set of preamble component sequences comprise preamble componentsequences Ga_(128,new,1) and Gb_(128,new,1). In some embodiments, thesecond set of preamble component sequences comprise mutual ZCZsequences. In some embodiments, the mutual ZCZ sequences comprisepreamble component sequences Ga_(128,new,2) and Gb_(128,new,2). In someembodiments, the second set of preamble component sequences comprisequadrature phase shift keying (QPSK) modulated preamble componentsequences. In some embodiments, the QPSK modulated preamble componentsequences comprise preamble component sequences A₁₂₈ and B₁₂₈.

In accordance with an embodiment, a method is provided. The methodincludes selecting a first Golay sequence from a first pair of Golaycomplementary sequences associated with first packet type, each Golaysequence of the first pair of Golay complementary sequences being zerocorrelation zone (ZCZ) sequences with each Golay sequence of a secondpair of Golay complementary sequences associated with a second packettype, and transmitting a wireless packet carrying a short training field(STF) that includes one or more instances of the first Golay sequence.

In some embodiments, the first pair of Golay complementary sequencescomprise preamble component sequences Ga_(128,new,1) and Gb_(128,new,1).In some embodiments, the first pair of Golay complementary sequencescomprise mutual ZCZ sequences. In some embodiments, the mutual ZCZsequences comprise preamble component sequences Ga_(128,new,2) andGb_(128,new,2). In some embodiments, the first pair of Golaycomplementary sequences comprise quadrature phase shift keying (QPSK)modulated Golay complementary sequences. In some embodiments, the QPSKmodulated Golay complementary sequences comprise preamble componentsequences A₁₂₈ and B₁₂₈. In some embodiments, transmitting the wirelesspacket comprises transmitting a real portion of the QPSK modulated Golaycomplementary sequences on a first antenna and transmitting an imaginaryportion of the QPSK modulated Golay complementary sequences on a secondantenna.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, and theadvantages thereof, reference is now made to the following descriptiontaken in conjunction with the accompanying drawings, in which:

FIG. 1 is a diagram of an embodiment wireless communications network;

FIG. 2 is a diagram of a packet;

FIGS. 3A and 3B show preamble component sequences for PHY packets;

FIGS. 4A and 4B are diagrams of a non-control STF and a control STF;

FIGS. 5A-5D are diagrams of correlation properties of STFs with variouspreamble component sequences;

FIGS. 6A-8B illustrate a first auto-detection scheme using STFs;

FIGS. 9A-11B illustrate a second auto-detection scheme using STFs;

FIGS. 12A-16B illustrate a third auto-detection scheme using STFs;

FIGS. 17A-21B illustrate a fourth auto-detection scheme using STFs;

FIGS. 22A-25B illustrate a fifth auto-detection scheme using STFs;

FIG. 26 is a diagram of an embodiment processing system; and

FIG. 27 is a block diagram of a transceiver.

Corresponding numerals and symbols in the different figures generallyrefer to corresponding parts unless otherwise indicated. The figures aredrawn to clearly illustrate the relevant aspects of the embodiments andare not necessarily drawn to scale.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The making and using of embodiments of this disclosure are discussed indetail below. It should be appreciated, however, that the conceptsdisclosed herein can be embodied in a wide variety of specific contexts,and that the specific embodiments discussed herein are merelyillustrative and do not serve to limit the scope of the claims. Further,it should be understood that various changes, substitutions andalterations can be made herein without departing from the spirit andscope of this disclosure as defined by the appended claims.

IEEE 802.11ay is currently being developed as an NG60 extension to IEEE802.11ad, with a goal of achieving extended throughput and range.Disclosed herein is a system and method for using short training fieldsto determine whether a received wireless physical (PHY) packet is anIEEE 802.11ay control packet, an IEEE 802.11ay non-control packet, anIEEE 802.11ad control packet, or an IEEE 802.11ad non-control packet.

In particular, STF fields in IEEE 802.11ay packets may be different fromSTF fields in IEEE 802.11ad packets such that a different numbers ofcross-correlation peaks result when the respective STFs arecross-correlated with one or more preamble component sequences. As aresult, an IEEE 802.11ay receiver may be able to distinguish IEEE802.11ay packets from IEEE 802.11ad packets by performingcross-correlation. For example, the IEEE 802.11ay receiver may determinea number of cross-correlation peaks between an STF in a packet and afirst preamble component sequence, and a number of cross-correlationpeaks between the STF in the packet and a second preamble componentsequence. The first preamble component sequence and the second preamblecomponent sequence may be complementary sequences that have anout-of-phase aperiodic autocorrelation coefficients sum that is zero. Inone embodiment, the first preamble component sequence and the secondpreamble component sequence form Golay pairs. The IEEE 802.11ay receivermay then determine whether the packet is an IEEE 802.11ay packet or anIEEE 802.11ad packet based on the numbers of correlation peaks betweenthe STF in the packet and the first and second pairs of preamblecomponent sequences. The IEEE 802.11ay receiver may determine that thepacket is an IEEE 802.11ad packet when a number of cross-correlationpeaks between the STF in the packet and the first preamble componentsequence exceeds a first threshold (e.g., 16 peaks) or when a number ofcross-correlation peaks between the STF in the packet and the secondpreamble component sequence exceeds a second threshold (e.g., 48 peaks).The IEEE 802.11ay receiver may determine that the packet is an IEEE802.11ay packet when a number of cross-correlation peaks between the STFin the packet and the second preamble component sequence exceeds a firstthreshold (e.g., 16 peaks) or when a number of cross-correlation peaksbetween the STF in the packet and the first preamble sequence exceeds asecond threshold (e.g., 48 peaks). Because embodiment 802.11ay packetscan be distinguished from 802.11ad packets, 802.11ad receivers maydiscard 802.11ay packets, rather than continuing to process incompatiblepackets, which may reduce power consumption at the 802.11ad receivers.Such savings may be accomplished without reprogramming existing 802.11adreceivers, because such receivers already work in a way that allows themto discard embodiment 802.11ay packets.

Other techniques for distinguishing IEEE 802.11ay packets from IEEE802.11ad packets are disclosed. In some embodiments, IEEE 802.11aypackets are transmitted using preamble component sequences that arephase-rotated variants of the preamble component sequences used totransmit IEEE 802.11ad packets. As a result, an IEEE 802.11ay receivermay be able to distinguish IEEE 802.11ay packets from IEEE 802.11adpackets by determining a number of cross-correlation peaks between anSTF in a packet and a pair of preamble component sequences, thenremoving a phase rotation from the STF and determining a number ofcross-correlation peaks between the phase-rotated STF and the same pairof preamble component sequences. The IEEE 802.11ay receiver may thendetermine whether the packet is an IEEE 802.11ay packet or an IEEE802.11ad packet according to whether the STF or the phase-rotated STFhas a higher degree of cross-correlation with the preamble componentsequences.

In some embodiments, preamble component sequences are selected for theSTFs of control and non-control 802.11ay packets such that thesepreamble component sequences for 802.11ay are mutual zero correlationzone (ZCZ) sequences with respective preamble component sequences for802.11ad. Preamble component sequences are sequences of symbolstransmitted in the preamble (e.g., STF, CEF) of a frame that are knownto a receiver and transmitter. The preamble component sequences in IEEE802.11ad and 802.11ay are Golay complimentary sequences. In someembodiments, preamble component sequences are selected for the STFs ofcontrol and non-control packets in an 802.11ay packet such that thesepreamble component sequences are mutual zero correlation zone (ZCZ)sequences with a zero correlation zone in a range of about 65time-domain symbol spacings. In some embodiments, the preamble componentsequences for control and non-control 802.11ay packets areQPSK-modulated for use in 802.11ay packets.

Various embodiments may achieve advantages. By performing auto-detectionin the STF, CEF, and/or header(s), a receiver may identify the format ofa received packet at an early stage of reception. In particular,auto-detection can be performed very early in the reception pipeline inembodiment Physical Layer Convergence Protocol (PLCP) Protocol DataUnits (PPDUs) that receive the STF before the CEF, header, or datafields. Additionally, proper selection of the STF and/or CEF of an802.11ay packet may permit legacy 802.11ad devices to detect the lengthand modulation coding scheme (MCS) of 802.11ay packets, which may reduceambiguity during auto-detection.

FIG. 1 is a diagram of a network 100 for communicating data. The network100 comprises an access point (AP) 110 having a coverage area 101, aplurality of mobile devices 120, and a backhaul network 130. As shown,the AP 110 establishes uplink (dashed line) and/or downlink (dottedline) connections with the mobile devices 120, which serve to carry datafrom the mobile devices 120 to the AP 110 and vice-versa. Data carriedover the uplink/downlink connections may include data communicatedbetween the mobile devices 120, as well as data communicated to/from aremote-end (not shown) by way of the backhaul network 130. As usedherein, the term “access point” refers to any component (or collectionof components) configured to provide wireless access in a network, suchas an evolved NodeB (eNB), a macro-cell, a femtocell, a Wi-Fi AP, orother wirelessly enabled devices. APs may provide wireless access inaccordance with one or more wireless communication protocols, e.g., LongTerm Evolution (LTE), LTE advanced (LTE-A), High Speed Packet Access(HSPA), Wi-Fi 802.11a/b/g/n/ac, etc. As used herein, the term “mobiledevice” refers to any component (or collection of components) capable ofestablishing a wireless connection with an access point, such as a userequipment (UE), a mobile station (STA), and other wirelessly enableddevices. In some embodiments, the network 100 may comprise various otherwireless devices, such as relays, low power nodes, etc. Embodimenttechniques may be performed on a receiver in the network 100, such asthe AP 110.

PPDUs are units of data transmitted over the physical (PHY) layer of anetwork, e.g., Layer 1 of the Open Systems Interconnection (OSI) model.PPDUs are structured data units that include information such as addressinformation, protocol-control information, and/or user data. The packetstructure of a PPDU typically includes a short training field (STF),channel estimation field (CEF), header field, and data payload. SomePPDUs may also include a legacy header field (L-Header) and an NG60header (N-Header) field. Auto-detection may be performed by detectingthe preamble of an 802.11ad PPDU, such as the STF and CEF, and/or theheader(s). In particular, the STF and CEF in 802.11ad use structuredbipolar-based complementary Golay sequences, which have severalbeneficial correlation properties that may be leverage by APs to enableauto-detection for 802.11ay networks.

FIG. 2 is a diagram of a packet 200. The packet 200 may be a wirelessPHY packet, and may be a control or non-control packet. Control PHYpackets typically carry control information in their payloads, andnon-control PHY packets typically carry data in their payloads.Non-control PHY packets may be transmitted using various waveforms, suchas single carrier (SC) waveforms and orthogonal frequency-divisionmultiplexed (OFDM) waveforms. A receiver may need to determine whetherthe packet 200 is a non-control or control PHY packet upon receiving thepacket 200. The receiver may also need to determine whether the packet200 is an 802.11ad or an 802.11ay packet.

The packet 200 includes a STF 202, a CEF 204, a header 206, a payload208, and training fields 210. It should be appreciated that the packet200 could include other fields. The STF 202 and the CEF 204 are commonlyreferred to in combination as a packet preamble 212. In someembodiments, the STF 202 is used to determine whether the packet 200 isa control or non-control PHY packet, and whether the packet is an802.11ad or an 802.11ay PHY packet.

The CEF 204 is used for channel estimation. If the packet 200 is anon-control packet, then the CEF 204 may also allow the receiver todetermine what kind of waveform was used to communicate the packet 200,e.g., an SC waveform or an OFDM waveform.

The header 206 may contain indicators or parameters that allow thereceiver to decode the payload 208. In some embodiments, the header 206may be used to determine whether the packet is an 802.11ad PHY packet oran 802.11ay PHY packet.

The payload 208 contains information (e.g., data) carried by the packet200. The training fields 210 may include other fields such as automaticgain control (AGC) and training (TRN) R/T subfields appended to thepacket 200.

FIGS. 3A and 3B show preamble component sequences for PHY packets. Thepreamble component sequences are bipolar-based Golay complementarysequences having a length of 128 symbols. The preamble componentsequences shown in FIG. 3A-B are referred to by IEEE 802.11ad as Ga₁₂₈and Gb₁₂₈, respectively. The sequences Ga₁₂₈ and Gb₁₂₈ are Golaysequences that form a complementary pair, and the subscript indicatesthe sequence length of 128. The preamble component sequences Ga₁₂₈ andGb₁₂₈ may be binary phase-shift keyed (BPSK), such that they are locatedat 0° and 180° on the unit circle, e.g., each symbol has a modulatedvalue of either 1 or −1. The preamble component sequences Ga₁₂₈ andGb₁₂₈ may be transmitted in the STF of a PHY packet, such as the STF 202of packet 200.

FIGS. 4A and 4B are diagrams of a non-control STF 400 and a control STF450, respectively, which are included in an 802.11ad packet preamble.The non-control STF 400 and the control STF 450 each include repeatedsequences 402, 452 and a termination sequence 404, 454. The control STF450 further includes a prefix sequence 456 after the terminationsequence 454.

The repeated sequences 402, 452 are multiple repetitions of the preamblecomponent sequences Ga₁₂₈ or Gb₁₂₈. The type and quantities of sequencesin the repeated sequences 402, 452 may be different between thenon-control STF 400 and a control STF 450 so that a receiver maydistinguish a non-control 802.11ad PHY packet from a control 802.11adPHY packet. For example, the repeated sequence 402 may be 16 repetitionsof the preamble component sequence Ga₁₂₈, and the repeated sequence 452may be 48 repetitions of the preamble component sequence Gb₁₂₈.

The termination sequences 404, 454 occur at the end of the repetitionportion of the non-control STF 400 and the control STF 450,respectively, and thus mark the end of the non-control STF 400 and thecontrol STF 450. As discussed above, an STF may include different valuesand have different lengths for a non-control or control PHY packet. Assuch, the termination sequences 404, 454 are predetermined sequencesthat indicate the end of an STF. The termination sequences 404, 454 arenegative instances of the preamble component sequence used in therepeated sequence 402, 452, e.g., where each symbol in the terminationsequences 404, 454 is multiplied by −1. For example, when the repeatedsequence 452 is several repetitions of the preamble component sequenceGb₁₂₈, then the termination sequence 454 is a negated preamble componentsequence −Gb₁₂₈. Accordingly, the preamble component sequences −Ga₁₂₈and −Gb₁₂₈ may be chosen, respectively, for the termination sequences404, 454.

The prefix sequence 456 occurs after the termination sequence 454 in thecontrol STF 450. The prefix sequence 456 is a preamble componentsequence −Ga₁₂₈ and is used as the cyclic prefix for the CEF 204. Thetermination sequence 404 of the non-control STF 400 also functions as aprefix sequence for the CEF 204, because the termination sequence 404 isalso the preamble component sequence −Ga₁₂₈.

FIGS. 5A and 5B are diagrams of correlation properties of thenon-control STF 400 and the control STF 450 with the preamble componentsequences Ga₁₂₈ and Gb₁₂₈, respectively. A receiver may performcross-correlation to determine whether a received sequence matches aknown sequence. For example, a receiver may cross-correlate a receivedSTF with the preamble component sequences Ga₁₂₈ and Gb₁₂₈ to determinewhich preamble component sequence is carried within the STF.

As shown in FIG. 5A, when the non-control STF 400 is correlated with thepreamble component sequence Ga₁₂₈, 16 positive impulses and a negativeimpulse are generated. The 16 positive impulses correspond tocorrelation peaks with the 16 positive repetitions of the preamblecomponent sequence Ga₁₂₈ in the repeated sequence 402, and the negativeimpulse corresponds to correlation peaks with the negative instance ofthe preamble component sequence Ga₁₂₈ in the termination sequence 406.The produced impulses are normalized to have a unit maximum magnitude,e.g., a maximum magnitude of 1 or −1. As shown in FIG. 5B, when thenon-control STF 400 is correlated with the preamble component sequenceGb₁₂₈, no correlation peaks are generated. Some noise may be generated,but the magnitude of the noise may not be large enough to register as acorrelation peak. As shown in FIGS. 5A and 5B, while the magnitude ofthe noise is low, there is still an appreciable amount of noise presenteven when no correlation peak is generated. Accordingly, bycross-correlating an STF in a received packet with both of the preamblecomponent sequences Ga₁₂₈ and Gb₁₂₈, a receiver may be able to determinewhether or not the packet is a non-control 802.11ad packet.

FIGS. 5C and 5D are diagrams of correlation properties of the controlSTF 450 with the preamble component sequences Ga₁₂₈ and Gb₁₂₈,respectively. As shown in FIG. 5C, when the control STF 450 iscorrelated with the preamble component sequence Ga₁₂₈, one negativecross-correlation peak is generated. This is because, as shown above,the control STF 450 contains one negative instance of the preamblecomponent sequence Ga₁₂₈. When the control STF 450 is correlated withthe preamble component sequence Gb₁₂₈, 48 positive impulses and anegative impulse are generated. These impulses correspond to the 48positive repetitions of the preamble component sequence Gb₁₂₈ in therepeated sequence 452 and the one negative instance of the preamblecomponent sequence Gb₁₂₈ in the prefix sequence 456. Accordingly, bycross-correlating an STF in a received packet with both of the preamblecomponent sequences Ga₁₂₈ and Gb₁₂₈, a receiver may be able to determinewhether or not the packet is an 802.11ad control packet.

Embodiment receivers may also auto-detect receipt of an 802.11ay packetusing the STF field. Accordingly, in some embodiments, STFs for 802.11aypackets may be selected such that they are different from STFs for802.11ad packets. Embodiment receivers may then perform auto-detectionof WLAN packets using the STF of received PHY packets. 802.11ay packetsmay be distinguished from 802.11ad packets using auto-detection schemes,according to autocorrelation and cross-correlation properties of theSTFs with various preamble component sequences.

FIGS. 6A-8B illustrate a first auto-detection scheme using STFs in whichthe preamble component sequences Ga₁₂₈ and Gb₁₂₈, which are used in802.11ad STFs, may also be used in 802.11ay STFs. In order todistinguish 802.11ay packets from 802.11ad packets, the preamblecomponent sequences Ga₁₂₈ and Gb₁₂₈ may be interchanged between controland non-control STFs in 802.11ay such that Ga₁₂₈ is used for therepeated sequences in an 802.11ay control packet and Gb₁₂₈ is used forthe repeated sequences in an 802.11ay non-control packet.

FIGS. 6A and 6B are diagrams of a non-control STF 600 and a control STF650, respectively, which are included in an 802.11ay packet preamble.The non-control STF 600 and the control STF 650 each include repeatedsequences 602, 652, a termination sequence 604, 654, and a prefixsequence 606, 656.

The repeated sequence 602 of the non-control STF 600 includes 16repetitions of the preamble component sequence Gb₁₂₈, and the controlSTF 650 includes 48 repetitions of the preamble component sequenceGa₁₂₈. The termination sequence 604, 654 in each STF includes a negativeinstance of the preamble component sequence used in the repeatedsequences 602, 652, i.e., the sequence 604 has one repetition of −Gb₁₂₈,and the sequence 654 has one repetition of −Ga₁₂₈.

In some embodiments, the prefix sequence 606, 656 is a predefinedsequence, such as −Ga₁₂₈, used above in the non-control STF 400 and thecontrol STF 450. Adding a single repetition of −Ga₁₂₈ to the control STF650 may assist in degrading channel estimation for an 802.11ad receiverthat receives an 802.11ay PHY packet. An 802.11ad receiver mayincorrectly identify a received control STF 650 as a non-control STFafter detecting the repeated sequences 652 and the termination sequence654. Adding a second repetition of −Ga₁₂₈ after the termination sequence654 prevents the 802.11ad receiver from successfully detecting the CEF204.

FIGS. 7A-7D are diagrams of cross-correlation properties for thenon-control STF 600 and the control STF 650 with the preamble componentsequences Gb₁₂₈ and Ga₁₂₈. FIG. 7A is a diagram of cross-correlationproperties of the non-control STF 600 with the preamble componentsequence Ga₁₂₈. FIG. 7B is a diagram of cross-correlation properties ofthe non-control STF 600 with the preamble component sequence Gb₁₂₈. FIG.7C is a diagram of cross-correlation properties of the control STF 650with the preamble component sequence Ga₁₂₈. FIG. 7D is a diagram ofcross-correlation properties of the control STF 650 with the preamblecomponent sequence Gb₁₂₈.

As shown in FIGS. 7A-7D and FIGS. 5A-5D, a relationship exists betweenthe PHY packet type of a received STF, and a number of peaks generatedwhen the received STF is cross-correlated with different preamblecomponent sequences. This relationship can be expressed as a lookuptable, as shown below in Table 1.

TABLE 1 Preamble Seq. Qty. Peaks Result Reference Ga₁₂₈ 16 802.11ad;non-control Figure 5A Gb₁₂₈ 48 802.11ad; control Figure 5D Gb₁₂₈ 16802.11ay; non-control Figure 7B Ga₁₂₈ 48 802.11ay; control Figure 7C

As shown above in Table 1, a received PHY packet type can be determinedby cross-correlating the STF with the preamble component sequences Ga₁₂₈and Gb₁₂₈ and counting the number of positive peaks in the correlationresult. Also included in Table 1 is a reference to the Figure numberthat shows a typical cross-correlation result for particular packet andframe types.

FIG. 8A is a diagram of an embodiment 802.11ay auto-detection method800. The 802.11ay auto-detection method 800 may be indicative ofoperations occurring in an 802.11ay receiver when determining the PHYpacket type of a received packet using the STF.

The 802.11ay auto-detection method 800 begins by correlating a receivedSTF with the preamble component sequences Ga₁₂₈ and Gb₁₂₈ (step 802).Next, the correlation peaks for each preamble component sequence aredetected and counted (step 804). If correlation of the received STFproduces about 48 peaks for the preamble component sequence Ga₁₂₈ orabout 16 peaks for the preamble component sequence Gb₁₂₈ (step 806), thepacket is identified as an 802.11ay packet (step 808). In cases wherecorrelation with one preamble component sequence produces peaks,correlation with the other sequence may produce other values that arenot considered peaks, such as noise or zero values. For example, asshown in FIGS. 7C and 7D if 48 peaks are produced when correlated withthe preamble component sequence Ga₁₂₈, then those 48 peaks will not beproduced when correlated with the preamble component sequence Gb₁₂₈.Next, demodulation and decoding of the packet is continued until the endof the 802.11ay packet (step 810).

If correlation of the STF produces 16 peaks for the preamble componentsequence Ga₁₂₈ or 48 peaks for the preamble component sequence Gb₁₂₈(step 812), the packet is identified as an 802.11ad packet (step 814).Finally, demodulation and decoding of the packet is continued until theend of the 802.11ad packet (step 816).

FIG. 8B is a diagram of embodiment 802.11ad auto-detection method 850.The 802.11ad auto-detection method 850 may be indicative of operationsoccurring in an 802.11ad receiver when determining the PHY packet typeof a received packet using the STF. Because an 802.11ad receiver may notbe capable of detecting 802.11ay packets, the 802.11ad auto-detectionmethod 850 may thus avoid incorrectly identifying a received 802.11aypacket as a compatible packet for an 802.11ad receiver.

The 802.11ad auto-detection method 850 begins by receiving an 802.11aySTF and correlating it with the preamble component sequences Ga₁₂₈ andGb₁₂₈ (step 852). Next, the correlation peaks for each preamblecomponent sequence are detected and counted (step 854). Next, thereceiver determines whether correlation of the STF with the preamblecomponent sequence Ga₁₂₈ produces 16 peaks (step 856). The correlationwith Ga₁₂₈ may not produce 16 peaks if, e.g., the STF is the non-controlSTF 600. In this case, a detection failure will occur when attempting tocount the correlation peaks for Gb₁₂₈ (step 858). The detection failuremay occur because an 802.11ad receiver expects correlation of a receivedSTF with the preamble component sequence Gb₁₂₈ to produce 48 peaks (fora control STF) or no peaks (for a non-control STF). However, as shown inFIG. 7B, correlation of the non-control STF 600 with the preamblecomponent sequence Gb₁₂₈ produces 16 peaks. Accordingly, an 802.11adreceiver produces a detection failure when attempting to detect thenon-control STF 600.

If, instead, correlation of the STF with the preamble component sequenceGa₁₂₈ produces 16 peaks, then the 802.11ad receiver will proceed toperform channel estimation and PHY header detection (step 860). Such astate may occur when the STF is the control STF 650. As shown in FIG.7C, correlation of the control STF 650 with Ga₁₂₈ produces 48 peaks;however, some 802.11ad receivers may detect the first 16 peaks of the 48correlated peaks and falsely identify the control STF 650 as thenon-control STF 400. In this case, detection failure will occur whenperforming PHY header detection (step 862). When a detection failure foreither the PHY header or STF occurs, then the 802.11ad auto-detectionmethod 850 terminates. Accordingly, use of the non-control STF 600 andthe control STF 650 in an 802.11ay PHY packet may allow an 802.11adreceiver to detect and discard 802.11ay PHY packets, notwithstanding thefact that an 802.11ad receiver may have no knowledge of the STF layoutfor 802.11ay packets.

FIGS. 9A-11B illustrate a second auto-detection scheme using STFs inwhich the preamble component sequences Ga₁₂₈ and Gb₁₂₈, which are usedin 802.11ad STFs, may be used in 802.11ay STFs. In order to distinguish802.11ay packets from 802.11ad packets, a phase rotation may be appliedto each bipolar symbol of the preamble component sequences Ga₁₂₈ andGb₁₂₈. The values in the repeated sequence 402 of the non-control STF400 can be expressed generally as:

(r₁, r₂, . . . , r₂₁₇₆)

where r_(n) ∈ {1, −1} and n=1, 2, . . . , 2176. Thus, when applying aphase rotation to each bipolar symbol, the values in the repeatedsequence for an 802.11ay non-control STF may be expressed generally as:

(r₁e^(jθ) ¹ , r₂e^(jθ) ² , . . . , r₂₁₇₆e^(jθ) ²¹⁷⁶ )

where θ_(n) ∈ (0, 2π) and n=1, 2, . . . , 2176.

Likewise, the values in the repeated sequence 452 of the control STF 450may be expressed generally as:

(r₁, r₂, . . . , r₆₄₀₀)

where r_(n) ∈ {1, −1} and n=1, 2, . . . , 6400. Thus, when applying aphase rotation to each bipolar symbol, the values in the repeatedsequence for an 802.11ay control STF may be expressed generally as:

(r₁e^(jθ) ¹ , r₂e^(jθ) ² , . . . , r₆₄₀₀e^(jθ) ⁶⁴⁰⁰ )

where θ_(n) ∈ (0, 2π) and n=1, 2, . . . , 6400.

As discussed above, each symbol in the preamble component sequencesGa₁₂₈ and Gb₁₂₈ has a modulated value of either 1 or −1. Thus each valueis linearly phase-rotated on the unit circle by values other than

$^{j\; \pi \frac{n}{2}}.$

For example, the values in the repeated sequence 402 of the non-controlSTF 400 may be expressed generally as:

${r_{STF}\left( {nT}_{c} \right)} = \left\{ \begin{matrix}{{{Ga}_{128}*\left( {n\mspace{14mu} {mod}\mspace{14mu} 128} \right)*^{j\; \pi \frac{n}{2}}},} & {{n = 0},1,\ldots \mspace{11mu},{{16*128} - 1}} \\{{{- {Ga}_{128}}*\left( {n\mspace{14mu} {mod}\mspace{14mu} 128} \right)*^{j\; \pi \frac{n}{2}}},} & {{n = {16*128}},\ldots \mspace{11mu},{{17*128} - 1}}\end{matrix} \right.$

Likewise, the values in the repeated sequence 452 of the control STF 450may be expressed generally as:

${r_{STF}\left( {nT}_{c} \right)} = \left\{ \begin{matrix}{{{Gb}_{128}*\left( {n\mspace{14mu} {mod}\mspace{14mu} 128} \right)*^{j\; \pi \frac{n}{2}}},} & {{n = 0},1,\ldots \mspace{14mu},{{48*128} - 1}} \\{{{- {Gb}_{128}}*\left( {n\mspace{14mu} {mod}\mspace{14mu} 128} \right)*^{j\; \pi \frac{n}{2}}},} & {{n = {48*128}},\ldots \mspace{14mu},{{49*128} - 1}} \\{{{- {Ga}_{128}}*\left( {n\mspace{14mu} {mod}\mspace{14mu} 128} \right)*^{j\; \pi \frac{n}{2}}},} & {{n = {49*128}},\ldots \mspace{14mu},{{50*128} - 1}}\end{matrix} \right.$

In other words, a different linear phase rotation, e^(jθ) ^(n) , may beselected and applied to the preamble component sequences Ga₁₂₈ andGb₁₂₈, e.g.,

$\theta_{n} \neq {\frac{n\; \pi}{2}.}$

Accordingly, in some embodiments, a linear phase rotation e^(jnφ) isused for 802.11ay, where

${\phi \neq \frac{\pi}{2}},{e.g.},{\phi = \frac{\pi}{4}},\frac{3\; \pi}{4},\frac{\pi}{8},\frac{3\pi}{8},\frac{5\pi}{8},$

etc. A receiver may determine whether a received packet is an 802.11ador an 802.11ay packet by cross-correlating the STF of the packet withthe preamble component sequences Ga₁₂₈ and Gb₁₂₈, and then removing aphase rotation from the STF of the packet and cross-correlating thede-rotated STF with the preamble component sequences Ga₁₂₈ and Gb₁₂₈.The receiver may then determine the packet type according to which STFhas a greater correlation with one or both of the preamble componentsequences Ga₁₂₈ and Gb₁₂₈, e.g., which STF produces an expected numberof peaks.

FIG. 9A is a diagram of an embodiment 802.11ay auto-detection method900. The 802.11ay auto-detection method 900 may be indicative ofoperations occurring on an 802.11ay receiver when determining the PHYpacket type of a received packet using the STF.

The 802.11ay auto-detection method 900 beings by de-rotating the phaseof a received STF by the phase shift used in IEEE 802.11ad, e.g.,

$^{{- j}\; \pi \frac{n}{2}}$

(step 902). Such a de-rotation may be done to first determine whetherthe received STF is a BPSK-modulated symbol, e.g., an 802.11ad PHY STF.Next, the de-rotated STF is correlated with the preamble componentsequences Ga₁₂₈ and Gb₁₂₈ (step 904). Next, the correlation peaks foreach preamble component sequence are detected and counted (step 906). Ifcorrelation of the received STF produces 16 peaks for the preamblecomponent sequence Ga₁₂₈ or 48 peaks for the preamble component sequenceGb₁₂₈ (step 908), the packet is identified as an 802.11ad packet (step910). Demodulation and decoding of the packet is continued until the endof the 802.11ad packet (step 912).

If correlation of the received STF does not produce 16 peaks for thepreamble component sequence Ga₁₂₈ or 48 peaks for the preamble componentsequence Gb₁₂₈, then the phase of the received STF is instead de-rotatedby the phase shift used in IEEE 802.11ay, e.g., e^(−jπφ) (step 914),where

$\phi \neq {\frac{\pi}{2}.}$

Next, the de-rotated STF is correlated with the preamble componentsequences Ga₁₂₈ and Gb₁₂₈ (step 916). Next, the correlation peaks foreach preamble component sequence are detected and counted (step 918). Ifcorrelation of the received STF produces 16 peaks for the preamblecomponent sequence Ga₁₂₈ or 48 peaks for the preamble component sequenceGb₁₂₈ (step 920), the packet is identified as an 802.11ay packet (step922). Finally, demodulation and decoding of the packet is continueduntil the end of the 802.11ay packet (step 924).

FIG. 9B is a diagram of an embodiment 802.11ad auto-detection method950. The 802.11ad auto-detection method 950 may be indicative ofoperations occurring in an 802.11ad receiver.

The 802.11ad auto-detection method 950 begins by de-rotating the phaseof a received 802.11ay STF by

$^{{- j}\; \pi \frac{n}{2}}$

(step 952). The phase is de-rotated by

$^{{- j}\; \pi \frac{n}{2}}$

because 802.11ad PHY packets contain BPSK-modulated symbols in theirSTFs, and so an 802.11ad receiver may only be capable of demodulatingBPSK-modulated STFs. Next, the received STF is correlated with thepreamble component sequences Ga₁₂₈ and Gb₁₂₈ (step 954). Next, anattempt is made to detect and count the correlation peaks for eachpreamble component sequence (step 956). Finally, a failure occurs whenattempting to count the correlation peaks. The failure occurs becausethe received 802.11ay STF may be modulated with a scheme other thanBPSK, e.g., the symbols in the preamble component sequence may belinearly phase-rotated. An 802.11ad receiver may not detect thesesymbols. Accordingly, embodiment STFs may not interfere with an existing802.11ad receiver.

In some embodiments, a block phase rotation phase rotation e^(jθ) ^(n)may be selected and applied to the preamble component sequences Ga₁₂₈and Gb₁₂₈ for an 802.11ay STF. That is, each of the preamble componentsequences Ga₁₂₈ and Gb₁₂₈ may be block-rotated to produce preamblecomponent sequences Ga_(128,k) and Gb_(128,k), where k is a value from 1to 17 for non-control STFs, and from 1 to 50 for control STFs.

FIGS. 10A and 10B are diagrams of a non-control STF 1000 and a controlSTF 1050, respectively, which are included in an 802.11ay packetpreamble. As shown, each symbol in the preamble component sequences forthe non-control STF 400 may be rotated by e^(jγ) ^(k) , where γ_(k)=kπfor k=1, . . . , 16, and γ₁₇=0. Likewise, each symbol in the preamblecomponent sequences for the control STF 450 may be rotated by e^(jφ)^(k) , where φ_(k)=kπ for k=1, . . . , 48, and φ₄₉=φ₅₀=0. Thus, eachpreamble component sequence in the repeated sequences 1002 may berepresented by Ga_(128,k)e^(jγ) ^(k) , where γ_(k) ∈ {0, 2π}, and eachpreamble component sequence in the repeated sequences 1052 may berepresented by Gb_(128,k)e^(jφ) ^(k) , where γ_(k) ∈ {0, 2π}.

FIG. 11A is a diagram of an embodiment 802.11ay auto-detection method1100. The 802.11ay auto-detection method 1100 may be indicative ofoperations occurring in an 802.11ay receiver.

The 802.11ay auto-detection method 1100 beings by de-rotating the phaseof a received STF by

$^{{- j}\; \pi \frac{n}{2}}$

(step 1102). Such a de-rotation may be done to first determine whetherthe received STF is a BPSK-modulated symbol, e.g., an 802.11ad PHY STF.Next, the de-rotated STF is correlated with the preamble componentsequences Ga₁₂₈ and Gb₁₂₈ (step 1104). Next, the correlation peaks foreach preamble component sequence are detected and counted (step 1106).If correlation of the received STF produces 16 peaks for the preamblecomponent sequence Ga₁₂₈ or 48 peaks for the preamble component sequenceGb₁₂₈ (step 1108), the packet is identified as an 802.11ad packet (step1110). Demodulation and decoding of the packet is continued until theend of the 802.11ad packet (step 1112).

If correlation of the received STF does not produce 16 peaks for thepreamble component sequence Ga₁₂₈ or 48 peaks for the preamble componentsequence Gb₁₂₈, then the phase of the received STF is instead blockde-rotated by e^(−jγ) ^(k) in for a non-control STF, or by e^(−jφ) ^(k)for a control STF (step 1114). Next, the block de-rotated STF iscorrelated with the preamble component sequences Ga₁₂₈ and Gb₁₂₈ (step1116). Next, the correlation peaks for each preamble component sequenceare detected and counted (step 1118). If correlation of the received STFproduces 16 peaks for the preamble component sequence Ga₁₂₈ or 48 peaksfor the preamble component sequence Gb₁₂₈ (step 1120), the packet isidentified as an 802.11ay packet (step 1122). Finally, demodulation anddecoding of the packet is continued until the end of the 802.11ay packet(step 1124).

FIG. 11B is a diagram of an embodiment 802.11ad auto-detection method1150. The 802.11ad auto-detection method 1150 may be indicative ofoperations occurring in an 802.11ad receiver.

The 802.11ad auto-detection method 1150 begins by de-rotating the phaseof a received 802.11ay STF by

$^{{- j}\; \pi \frac{n}{2}}$

(step 1152). The phase is de-rotated by

$^{{- j}\; \pi \frac{n}{2}}$

because 802.11ad receivers may only be capable of decodingBPSK-modulated symbols in an STF. Next, the received STF is correlatedwith the preamble component sequences Ga₁₂₈ and Gb₁₂₈ (step 1154). Next,an attempt is made to detect and count the correlation peaks for eachpreamble component sequence (step 1156). Finally, a failure occurs whenattempting to count the correlation peaks. The failure occurs becausethe received 802.11ay STF may be modulated with a scheme other thanBPSK, e.g., the symbols in the preamble component sequence may be blockphase-rotated. An 802.11ad receiver may not detect these symbols.Accordingly, embodiment STFs may not interfere with an existing 802.11adreceiver.

FIGS. 12A-16B illustrate a third auto-detection scheme using STFs inwhich new preamble component sequences are selected for the control andnon-control STFs in an 802.11ay PHY packet. In some embodiments, newpreamble component sequences Ga_(128,new,1) and Gb_(128,new,1) areselected such that they are zero correlation zone (ZCZ) sequences withGa₁₂₈ and Gb₁₂₈, respectively. Ideal ZCZ sequences have an impulsesignal (e.g., values of 1 when in-phase and 0 when out-of-phase) whenautocorrelated, and a value of 0 when cross-correlated in a certainrange of shifts.

FIGS. 12A and 12B show embodiment preamble component sequencesGa_(128,new,1) and Gb_(128,new,1). The ZCZ properties of the preamblecomponent sequences Ga_(128,new,1) and Gb_(128,new,1) may allow thesequences to be used as replacements for the preamble componentsequences Ga₁₂₈ and Gb₁₂₈ in the repeated sequences 402 and 452 of thenon-control STF 400 and the control STF 450, respectively.

FIGS. 13A-13H are diagrams of various correlation properties of thepreamble component sequences Ga_(128,new,1) and Gb_(128,new,1) with thepreamble component sequences Ga₁₂₈ and Gb₁₂₈. FIGS. 13A and 13B arediagrams of autocorrelation properties of Ga_(128,new,1) andGb_(128,new,1), respectively. As shown, the autocorrelation results areimpulse responses for shifts within [−32, 32] symbol time slots, andhave no correlation for shifts within [−32, 32] symbol time slots.Further, the side lobes for each autocorrelation signal are relativelylow. Both the impulse response and the side lobes that result fromautocorrelation of Ga_(128,new,1) and Gb_(128,new,1) are comparable tothe impulse response and the side lobes that result from autocorrelationof Ga₁₂₈ and Gb₁₂₈, previously shown in the zoomed portions of FIGS. 5Aand 5C. It should be appreciated that, although FIGS. 13A-13H illustrateideal impulse responses, autocorrelation results may not produce trueimpulses, but rather may produce responses that are of sufficientmagnitude for a receiver to recognize the values as correlation peaks.

FIGS. 13C and 13D are diagrams of cross-correlation properties ofGa_(128,new,1) and Gb_(128,new,1), respectively. The cross-correlationproperties of Ga_(128,new,1) and Gb_(128,new,1) are comparable to thecross-correlations between Ga₁₂₈ and Gb₁₂₈.

FIGS. 13E and 13F are diagrams of cross-correlation properties betweenGa_(128,new,1) and Ga₁₂₈, and between Gb_(128,new,1) and Gb₁₂₈,respectively. As shown, the cross-correlations are equal to zero forshifts within [−32, 32]. Unlike the cross-correlation between Ga₁₂₈ andGb₁₂₈ (illustrated above in FIG. 5B), there is no noise in the zerocorrelation zone range for Ga_(128,new,1) and Gb_(128,new,1).Accordingly, an 802.11ad receiver will not detect a false positive whenattempting to correlate Ga₁₂₈ or Gb₁₂₈ with Ga_(128,new,1) orGb_(128,new,1), respectively.

FIGS. 13G and 13H are diagrams of cross-correlation properties betweenGa_(128,new,1) and Gb₁₂₈, and between Gb_(128,new,1) and Ga₁₂₈,respectively. The cross-correlation properties between Ga_(128,new,1)and Gb₁₂₈, and between Gb_(128,new,1) and Ga₁₂₈ are comparable to thecross-correlations between Ga₁₂₈ and Gb₁₂₈.

FIGS. 14A and 14B are diagrams of a non-control STF 1400 and a controlSTF 1450, respectively, which are included in an 802.11ay packetpreamble. The non-control STF 1400 and the control STF 1450 each includerepeated sequences 1402, 1452, a termination sequence 1404, 1454 whichindicates the end of the non-control STF 1400 and the control STF 1450,respectively, and a prefix sequence 1406, 1456.

The repeated sequences 1402, 1452 include multiple repetitions ofpreamble component sequences. The repeated sequence 1402 includes 16repetitions of the preamble component sequence Ga_(128,new,1), and therepeated sequence 1452 includes 48 repetitions of the preamble componentsequence Gb_(128,new,1). It should be appreciated that the repeatedsequences 1402, 1452 could contain any preamble component sequence andnumber of repetitions.

The termination sequence 1404, 1454 occurs after the repeated sequences1402, 1452. The termination sequence 1404, 1454 includes one negativeinstance of the preamble component sequences included in the repeatedsequences 1402, 1452. For example, in embodiments where the repeatedsequence 1402 includes several repetitions of the preamble componentsequence Ga_(128,new,1), the termination sequence 1404 includes onerepetition of −Ga_(128,new,1). Likewise, in embodiments where therepeated sequence 1452 includes several repetitions of the preamblecomponent sequence Gb_(128,new,1), the sequence 1454 includes onerepetition of −Gb_(128,new,1).

The prefix sequence 1406, 1456 is a cyclic prefix of CEF. It should benoted that the prefix sequence 1406, 1456, i.e., the final preamblecomponent sequence (−Ga₁₂₈) before the CEF, may be the same preamblecomponent sequence at the end of the non-control STF 400 and the controlSTF 450.

FIGS. 15A-15D are diagrams of cross-correlation properties for thenon-control STF 1400 with various preamble component sequences. Asshown, the non-control STF 1400 produces 16 positive peaks and anegative peak when correlated with the preamble component sequenceGa_(128,new,1), and produces one negative peak when correlated with thepreamble component sequence Ga₁₂₈, but otherwise does not produce asignificant signal when correlated with other preamble componentsequences. The values produced by cross-correlations of the non-controlSTF 1400 with sequences other than Ga_(128,new,1) and Ga₁₂₈ may includesome noise, but the magnitude of the noise may not be large enough toregister as a correlation peak.

FIGS. 15E-15H are diagrams of cross-correlation properties for thecontrol STF 1450 with various preamble component sequences. As shown,the control STF 1450 produces 48 positive peaks and a negative peak whencorrelated with the preamble component sequence Gb_(128,new,1), andproduces one negative peak when correlated with preamble componentsequence Ga₁₂₈, but otherwise does not produce a significant signal. Thevalues produced by cross-correlations of the control STF 1450 withsequences other than Gb_(128,new,1) may include some noise, but themagnitude of the noise may not be large enough to register as acorrelation peak. Accordingly, proper selection of the symbols for thepreamble component sequences used in the non-control STF 1400 and thecontrol STF 1450 may allow the STFs to be auto-detected by a receiverthat correlates the STFs with the preamble component sequencesGa_(128,new,1) and Gb_(128,new,1) (e.g., an 802.11ay receiver), but maynot interfere with a receiver that correlates the STFs with the preamblecomponent sequences Ga₁₂₈ and Gb₁₂₈ (e.g., an 802.11ad receiver).

FIG. 16A is a diagram of an embodiment 802.11ay auto-detection method1600. The 802.11ay auto-detection method 1600 may be indicative ofoperations occurring in an 802.11ay receiver when determining the PHYpacket type of a received packet using the STF.

The 802.11ay auto-detection method 1600 begins by receiving a STF andcorrelating it with the preamble component sequences Ga_(128,new,1),Gb_(128,new,1), Ga₁₂₈, and Gb₁₂₈ (step 1602). Next, the correlationpeaks for each preamble component sequence are detected and counted(step 1604). If correlation of the received STF produces 16 peaks forthe preamble component sequence Ga_(128,new,1) or 48 peaks for thepreamble component sequence Gb_(128,new,1) (step 1606), the packet isidentified as an 802.11ay packet (step 1608). In cases where correlationwith one preamble component sequence produces peaks, correlation withthe other sequence may produce lower values that have no significance.For example, if 16 peaks are produced when correlated with the preamblecomponent sequence Ga_(128,new,1), then no values are produced whencorrelated with the preamble component sequence Gb_(128,new,1). Next,demodulation and decoding of the packet is continued until the end ofthe 802.11ay packet (step 1610).

If instead, correlation of the STF produces 16peaks for the preamblecomponent sequence Ga₁₂₈ or 48 peaks for the preamble component sequenceGb₁₂₈ (step 1612), the packet is identified as an 802.11ad packet (step1614). Finally, demodulation and decoding of the packet is continueduntil the end of the 802.11ad packet (step 1616).

FIG. 16B is a diagram of an embodiment 802.11ad auto-detection method1650. The 802.11ad auto-detection method 1650 may be indicative ofoperations occurring in an 802.11ad receiver when determining the PHYpacket type of a received packet using the STF. Because an 802.11adreceiver may not capable of responding to 802.11ay traffic, the 802.11adauto-detection method 1650 may thus avoid incorrectly identifying areceived 802.11ay packet as a compatible packet for an 802.11adreceiver.

The 802.11ad auto-detection method 1650 begins by receiving an 802.11aySTF and correlating it with the preamble component sequences Ga₁₂₈ andGb₁₂₈ (step 1652). Next, the correlation peaks for each preamblecomponent sequence are detected and counted (step 1654). Next, anattempt to detect positive peaks in the correlated preamble componentsequences is attempted, but fails (step 1656). Detection fails becausethe received STFs contain the preamble component sequence Ga_(128,new,1)and Gb_(128,new,1), which are ZCZ sequences with Ga₁₂₈ and Gb₁₂₈, asshown in FIGS. 13E and 13F, and thus correlation does not producesignificant values. Finally, the failed STF detection causes asynchronization failure (step 1658). Thus, the 802.11ad auto-detectionmethod 1650 allows an 802.11ad receiver to fail auto-detection when itreceives an incompatible 802.11ay PHY packet, causing the receiver toignore the remainder of the PHY packet.

FIGS. 17A-21B illustrate a fourth auto-detection scheme using STFs inwhich new preamble component sequences are selected for the control andnon-control STFs in an 802.11ay PHY packet. In some embodiments, newpreamble component sequences Ga_(128,new,2) and Gb_(128,new,2) areselected such that they are mutual zero correlation zone (ZCZ)sequences, e.g., the sequences produce no correlation peaks whencross-correlated in a certain range of shifts.

FIGS. 17A and 17B show embodiment preamble component sequencesGa_(128,new,2) and Gb_(128,new,2). The mutual ZCZ properties of thepreamble component sequences Ga_(128,new,2) and Gb_(128,new,2) allowsthe sequences to be used as replacements for the preamble componentsequences Ga₁₂₈ and Gb₁₂₈ in the repeated sequences 402, 452 of thenon-control STF 400 and the control STF 450. Because the preamblecomponent sequences Ga_(128,new,2) and Gb_(128,new,2) produce nocorrelation peaks when cross-correlated, there may be a reducedpossibility of incorrectly identifying a PHY packet as a control ornon-control packet based on the STF.

FIG. 18A-18C are diagrams of various correlation properties of thepreamble component sequences Ga_(128,new,2) and Gb_(128,new,2). FIGS.18A and 18B show autocorrelation properties of Ga_(128,new,2) andGb_(128,new,2), respectively. As shown, the autocorrelations have animpulse response property. Further, values at the side lobes of eachautocorrelation are relatively low, and may be even lower than values atthe side lobes of autocorrelations for the preamble component sequencesGa_(128,new,2) and Gb_(128,new,2) (shown in FIGS. 13A and 13B). Both theimpulse response and side lobes for Ga_(128,new,2) and Gb_(128,new,2)are comparable to the impulse response and side lobes for Ga₁₂₈ andGb₁₂₈, previously shown in the zoomed portions of FIGS. 5A and 5C.

FIG. 18C is a diagram of a cross-correlation property of Ga_(128,new,2)and Gb_(128,new,2). Ga_(128,new,2) and Gb_(128,new,2) have a higherdegree of correlation than the cross-correlation between Ga₁₂₈ andGb₁₂₈. As shown in FIG. 18C, the cross-correlation of the preamblecomponent sequences Ga_(128,new,2) and Gb_(128,new,2) producesrelatively low values.

FIGS. 19A and 19B are diagrams of a non-control STF 1900 and a controlSTF 1950, respectively, which are included in an 802.11ay packetpreamble. The non-control STF 1900 and the control STF 1950 each includerepeated sequences 1902, 1952, a termination sequence 1904, 1954, and aprefix sequence 1906, 1956.

The repeated sequences 1902, 1952 include multiple repetitions of thepreamble component sequences. The repeated sequence 1902 includes 16repetitions of the preamble component sequence Ga_(128,new,2), and therepeated sequence 1952 includes 48 repetitions of the preamble componentsequence Gb_(128,new,2). It should be appreciated that the repeatedsequences 1902, 1952 could contain any preamble component sequence andnumber of repetitions, as discussed further below.

The termination sequence 1904, 1954 occurs after the repeated sequences1902, 1952. The sequence 1904, 1954 includes one negative instance ofthe preamble component sequences included in the repeated sequences1902, 1952. For example, in embodiments where the repeated sequence 1902includes several repetitions of the preamble component sequenceGa_(128,new,2), the sequence 1904 includes one repetition of−Ga_(128,new,2). Likewise, in embodiments where the repeated sequence1952 includes several repetitions of the preamble component sequenceGb_(128,new,2), the sequence 1954 includes one repetition of−Gb_(128,new,2).

The prefix sequence 1906, 1956 indicates the end of the non-control STF1900 and the control STF 1950, respectively. It should be noted that theprefix sequence 1906, 1956, i.e., the final preamble component sequence(−Ga₁₂₈) before the CEF, may be the same as the final sequence in thenon-control STF 400 and the control STF 450. Accordingly, an 802.11adreceiver may still be capable of identifying the end of an 802.11ay STF,even though an 802.11ad receiver may not be completely compatible with802.11ay PHY packets. The prefix sequence 1906, 1956 is a cyclic prefixfor the CEF 204.

FIGS. 20A-20D show cross-correlation properties for the non-control STF1900 and the control STF 1950 with the preamble component sequencesGa_(128,new,2) and Gb_(128,new,2). As shown, the non-control STF 1900produces 16positive peaks and a negative peak when correlated with thepreamble component sequence Ga_(128,new,2), but otherwise does notproduce a significant signal when correlated with other preamblecomponent sequences. Likewise, the control STF 1950 produces 48 positivepeaks and a negative peak when correlated with the preamble componentsequence Gb_(128,new,2), but otherwise does not produce a significantsignal when correlated with other preamble component sequences. Thevalues produced by cross-correlations of the non-control STF 1900 andthe control STF 1950 with sequences other than Ga_(128,new,2) andGb_(128,new,2) may include some noise, but the magnitude of the noisemay not be large enough to register as a correlation peak. Accordingly,proper selection of the symbols for the preamble component sequencesused in the non-control STF 1900 and the control STF 1950 may allow theSTFs to be auto-detected by a receiver that correlates the STFs with thepreamble component sequences Ga_(128,new,2) and Gb_(128,new,2) (e.g., an802.11ay receiver), but may not interfere with a receiver thatcorrelates the STFs with the preamble component sequences Ga₁₂₈ andGb₁₂₈ (e.g., an 802.11ad receiver). Cross-correlation properties of thenon-control STF 1900 and the control STF 1950 with other preamblecomponent sequences (e.g., Ga₁₂₈, Gb₁₂₈) may be similar to propertiesdiscussed above with respect to FIGS. 15A-15H. Because Ga_(128,new,2)and Gb_(128,new,2) are mutual ZCZ sequences, they produce less noisewhen cross-correlated than Ga_(128,new,1) and Gb_(128,new,1). Forexample, FIG. 20A contains the same quantity of peaks as FIG. 15A, buthas less noise.

FIG. 21A is a diagram of an embodiment 802.11ay auto-detection method2100. The 802.11ay auto-detection method 2100 may be indicative ofoperations occurring in an 802.11ay receiver when determining the PHYpacket type of a received packet using the STF.

The 802.11ay auto-detection method 1600 begins by receiving a STF andcorrelating it with the preamble component sequences Ga_(128,new,2),Gb_(128,new,2), Ga₁₂₈, and Gb₁₂₈ (step 2102). Next, the correlationpeaks for each preamble component sequence are detected and counted(step 2104). If correlation of the received STF produces 16 peaks forthe preamble component sequence Ga_(128,new,2) or 48 peaks for thepreamble component sequence Gb_(128,new,2) (step 2106), the packet isidentified as an 802.11ay packet (step 2108). In cases where correlationwith one preamble component sequence produces peaks, correlation withthe other sequence may produce lower values that have no significance.For example, if 16 peaks are produced when correlated with the preamblecomponent sequence Ga_(128,new,2), then no values are produced whencorrelated with the preamble component sequence Gb_(128,new,2). Next,demodulation and decoding of the packet is continued until the end ofthe 802.11ay packet (step 2110).

If instead, correlation of the STF produces 16peaks for the preamblecomponent sequence Ga₁₂₈ or 48 peaks for the preamble component sequenceGb₁₂₈ (step 2112), the packet is identified as an 802.11ad packet (step2114). Finally, demodulation and decoding of the packet is continueduntil the end of the 802.11ad packet (step 2116).

FIG. 21B is a diagram of an embodiment 802.11ad auto-detection method2150. The 802.11ad auto-detection method 2150 may be indicative ofoperations occurring in an 802.11ad receiver when determining the PHYpacket type of a received packet using the STF. Because an 802.11adreceiver may not capable of detecting 802.11ay packet, the 802.11adauto-detection method 2150 may thus avoid incorrectly identifying areceived 802.11ay packet as a compatible packet for an 802.11adreceiver.

The 802.11ad auto-detection method 2150 begins by receiving an 802.11aySTF and correlating it with the preamble component sequences Ga₁₂₈ andGb₁₂₈ (step 2152). Next, the correlation peaks for each preamblecomponent sequence are detected and counted (step 2154). Next, anattempt to detect positive peaks in the correlated preamble componentsequences is attempted, but fails (step 2156). Detection fails becausethe received STFs contain the preamble component sequence Ga_(128,new,2)and Gb_(128,new,2), which are mutual ZCZ sequences and do not correlatewith Ga₁₂₈ and Gb₁₂₈, as shown in FIGS. 20C-20D and 20G-20H. Finally,the failed detection causes a synchronization failure (step 2158). Thus,the 802.11ad auto-detection method 2150 allows an 802.11ad receiver togracefully fail auto-detection and continue operating when it receivesan incompatible 802.11ay PHY packet.

FIGS. 22A-25B illustrate a fifth auto-detection scheme using STFs inwhich new preamble component sequences are selected for the control andnon-control STFs in an 802.11ay PHY packet. In some embodiments, newpreamble component sequences A₁₂₈ and B₁₂₈ are selected such that thesequences are quadrature phase shift keying (QPSK) modulated variants ofthe preamble component sequences Ga₁₂₈ and Gb₁₂₈.

FIGS. 22A-22B show embodiment preamble component sequences A₁₂₈ andB₁₂₈, respectively. The preamble component sequences A₁₂₈ and B₁₂₈ arechosen such that

A ₁₂₈ =α·Ga ₁₂₈ +β·Ga _(128,new,1) ·e ^(jπ/2)

and

B ₁₂₈ =α·Gb ₁₂₈ +β·Gb _(128,new,1) ·e ^(jπ/2)

where 0<α, β<1, α²+β²=1. Thus, the preamble component sequences A₁₂₈ andB₁₂₈ are QPSK-modulated. This allows the preamble component sequencesA₁₂₈ and B₁₂₈ to be backwards-compatible with other wireless techniques.In some embodiments, the preamble component sequences Ga_(128,new,1) andGb_(128,new,1) may be interchanged such that the imaginary portions ofA₁₂₈ and B₁₂₈ are replaced with one another to produce preamblecomponent sequences A₁₂₈′ and B₁₂₈′ such that

A ₁₂₈ ′=α·Ga ₁₂₈ +β·Gb _(128,new,1) ·e ^(jπ/2)

and

B ₁₂₈ ′=α·Gb ₁₂₈ +β·Ga _(128,new,1) ·e ^(jπ/2)

where 0<α, β<1, α²+β²=1. It should be appreciated that in someembodiments A₁₂₈ and B₁₂₈ may be interchanged. Because the preamblecomponent sequences A₁₂₈ and B₁₂₈ are QPSK-modulated variants of thepreamble component sequences Ga₁₂₈ and Gb₁₂₈, correlation of thepreamble component sequences A₁₂₈ and B₁₂₈ with Ga₁₂₈ and Gb₁₂₈,respectively, may produce values that are equivalent to impulseresponses in a certain range of shifts.

FIGS. 23A and 23B are diagrams of a non-control STF 2300 and a controlSTF 2350, respectively, which are included in an 802.11ay packetpreamble. The non-control STF 2300 and the control STF 2350 each includerepeated sequences 2302, 2352 and a termination sequence 2306, 2356. Thecontrol STF 2350 also includes a sequence 2354 interposed between therepeated sequence 2352 and the termination sequence 2356. In someembodiments, the non-control STF 2300 may also include a sequence afterthe repeated sequence 2302.

The repeated sequences 2302, 2352 include multiple repetitions of thepreamble component sequences. The repeated sequence 2302 includes 16repetitions of the preamble component sequence A₁₂₈, and the repeatedsequence 2352 includes 48 repetitions of the preamble component sequenceB₁₂₈. It should be appreciated that the repeated sequences 2302, 2352could contain any preamble component sequence and number of repetitions.

The sequence 2354 occurs after the repeated sequence 2352. The sequence2354 includes one negative instance of the preamble component sequencesincluded in the repeated sequence 2352. For example, in embodimentswhere the repeated sequence 2352 includes several repetitions of thepreamble component sequence B₁₂₈, the sequence 2354 includes onerepetition of −B₁₂₈.

The termination sequence 2306, 2356 is used as a cyclic prefix for theCEF 204 in the non-control STF 2300 and the control STF 2350,respectively. It should be noted that the termination sequence 2306,2356, i.e., the final preamble component sequence (−Ga₁₂₈) before theCEF, may be the same as the final preamble component sequence (−Ga₁₂₈)before the CEF the non-control STF 400 and the control STF 450.

Because the preamble component sequences A₁₂₈ and B₁₂₈ areQPSK-modulated variants of the preamble component sequences Ga₁₂₈ andGb₁₂₈, correlation of the non-control STF 2300 with Ga₁₂₈ by a receivermay produce 16 positive peaks and one negative peak, and correlation ofthe control STF 2350 with Gb₁₂₈ by a receiver may produce 48 positivepeaks and one negative peak.

FIG. 24A is a diagram of an embodiment 802.11ay auto-detection method2400. The 802.11ay auto-detection method 2400 may be indicative ofoperations occurring in an 802.11ay receiver when determining the PHYpacket type of a received packet using the STF.

The 802.11ay auto-detection method 2400 begins by receiving a STF andcorrelating it with the preamble component sequences A₁₂₈, B₁₂₈, Ga₁₂₈,and Gb₁₂₈ (step 2402). Next, the correlation peaks for each preamblecomponent sequence are detected and counted (step 2404). If correlationof the received STF produces 16peaks for the preamble component sequenceGa₁₂₈ or 48 peaks for the preamble component sequence Gb₁₂₈ (step 2406),the packet is identified as one of an 802.11ay packet or an 802.11adpacket. If correlation peaks are not detected for either of the preamblecomponent sequences Ga₁₂₈ or Gb₁₂₈, then the 802.11ay auto-detectionmethod 2400 concludes. Such a failure may occur, for example, when an802.11ay receiver receives an incompatible PHY packet.

If correlation peaks are detected for the either of the preamblecomponent sequences Ga₁₂₈ or Gb₁₂₈, the 802.11ay auto-detection method2400 continues by determining whether correlation of the received STFproduces 16 peaks for the preamble component sequence A₁₂₈ or 48 peaksfor the preamble component sequence B₁₂₈ (step 2408). If so, the packetis identified as an 802.11ay packet (step 2410). Next, demodulation anddecoding of the packet is continued until the end of the 802.11ay packet(step 2412).

If correlation of the received STF does not produce 16 peaks for thepreamble component sequence A₁₂₈ or 48 peaks for the preamble componentsequence B₁₂₈, then the packet is identified as an 802.11ad packet (step2414). Finally, demodulation and decoding of the packet is continueduntil the end of the 802.11ad packet (step 2416). Accordingly, an802.11ay receiver may be capable of detecting reception of a compatiblePHY packet by correlating its STF with Ga₁₂₈ and Gb₁₂₈, and then furthercorrelating the received STF with A₁₂₈ and B₁₂₈ to auto-detect thereceived PHY packet type.

FIG. 24B is a diagram of an embodiment 802.11ad auto-detection method2450. The 802.11ad auto-detection method 2450 may be indicative ofoperations occurring in an 802.11ad receiver when determining the PHYpacket type of a received packet using the STF. Because an 802.11adreceiver may not capable of detecting an 802.11ay packet, the 802.11adauto-detection method 2450 may thus avoid incorrectly identifying areceived 802.11ay packet as a compatible packet for an 802.11adreceiver.

The 802.11ad auto-detection method 2450 begins by receiving an 802.11aySTF and correlating it with the preamble component sequences Ga₁₂₈ andGb₁₂₈ (step 2452). Next, the correlation peaks for each preamblecomponent sequence are detected and counted (step 2454). If correlationof the received STF does not produce 16 peaks for the preamble componentsequence Ga₁₂₈ or 48 peaks for the preamble component sequence Gb₁₂₈(step 2456), then auto-detection fails and the 802.11ad auto-detectionmethod 2450 concludes.

However, if correlation of the received STF produces 16 peaks for thepreamble component sequence Ga₁₂₈ or 48 peaks for the preamble componentsequence Gb₁₂₈ (step 2456), then channel estimation and L-Headerdetection of the received 802.11ay PHY packet is performed (step 2458).Next, the PHY packet length and the MCS of the L-Header is detected(Step 2460). Next, a detection failure occurs when detecting theN-Header because the 802.11ad receiver is incompatible with an 802.11ayPHY packet (step 2462). Finally, this failure causes the receiver toenter power save mode until the end of the current PHY packet isdetected. Accordingly, an 802.11ad receiver may be capable of detectingreception of either an 802.11ay or an 802.11ad PHY packet during STFcorrelation, and then may gracefully fail auto-detection of anincompatible 802.11ay PHY packet after STF detection and during channelestimation and header detection. By failing auto-detection at a laterstage, an 802.11ad receiver may be able to enter power save mode afterreceiving an incompatible PHY packet, increasing power efficiency of thereceiver.

FIGS. 25A and 25B are diagrams of antenna transmission configurations2500, 2550 for a non-control STF and a control STF, respectively. Theantenna transmission configuration 2500 may be indicative of signalstransmitted to produce the non-control STF 2300. Likewise, the antennatransmission configuration 2550 may be indicative of signals transmittedto produce the control STF 2350. Because the preamble componentsequences A₁₂₈ and B₁₂₈ are QPSK-modulated variants of the preamblecomponent sequences Ga₁₂₈ and Gb₁₂₈, an 802.11ay transmitter may producethe non-control STF 2300 and the control STF 2350 by transmittingorthogonal variants of the non-control STF 400 and the control STF 450,respectively. The orthogonal sequences may be combined by transmittingeach sequence on a different antenna. For example, a real portion of thepreamble component sequences A₁₂₈ and B₁₂₈ may be transmitted on a firstantenna, and an imaginary portion of the preamble component sequencesA₁₂₈ and B₁₂₈ may be transmitted on a second antenna.

Because one of each of the transmitted sequences includes the preamblecomponent sequences Ga₁₂₈ and Gb₁₂₈, and 802.11ad receiver may thusreceive the incompatible PHY packets and perform channel estimation andheader detection of the PHY packet before failing auto-detection andentering power save mode. Likewise, an 802.11ay receiver may receive thePHY packet and perform auto-detection by correlating with the preamblecomponent sequences A₁₂₈, B ₁₂₈, Ga₁₂₈, and Gb₁₂₈. Auto-detection of thereceived PHY packets by a receiver may be performed using a methodsimilar to the 802.11ay auto-detection method 2400 and the 802.11adauto-detection method 2450, discussed above.

FIG. 26 is a block diagram of an embodiment processing system 2600 forperforming methods described herein, which may be installed in a hostdevice. As shown, the processing system 2600 includes a processor 2602,a memory 2604, and interfaces 2606-2610, which may (or may not) bearranged as shown in FIG. 26. The processor 2602 may be any component orcollection of components adapted to perform computations and/or otherprocessing related tasks, and the memory 2604 may be any component orcollection of components adapted to store programming and/orinstructions for execution by the processor 2602. In an embodiment, thememory 2604 includes a non-transitory computer readable medium. Theinterfaces 2606, 2608, 2610 may be any component or collection ofcomponents that allow the processing system 2600 to communicate withother devices/components and/or a user. For example, one or more of theinterfaces 2606, 2608, 2610 may be adapted to communicate data, control,or management messages from the processor 2602 to applications installedon the host device and/or a remote device. As another example, one ormore of the interfaces 2606, 2608, 2610 may be adapted to allow a useror user device (e.g., personal computer (PC), etc.) tointeract/communicate with the processing system 2600. The processingsystem 2600 may include additional components not depicted in FIG. 26,such as long term storage (e.g., non-volatile memory, etc.).

In some embodiments, the processing system 2600 is included in a networkdevice that is accessing, or part otherwise of, a telecommunicationsnetwork. In one example, the processing system 2600 is in a network-sidedevice in a wireless or wireline telecommunications network, such as abase station, a relay station, a scheduler, a controller, a gateway, arouter, an applications server, or any other device in thetelecommunications network. In other embodiments, the processing system2600 is in a user-side device accessing a wireless or wirelinetelecommunications network, such as a mobile station, a user equipment(UE), a personal computer (PC), a tablet, a wearable communicationsdevice (e.g., a smartwatch, etc.), or any other device adapted to accessa telecommunications network.

In some embodiments, one or more of the interfaces 2606, 2608, 2610connects the processing system 2600 to a transceiver adapted to transmitand receive signaling over the telecommunications network. FIG. 27 is ablock diagram of a transceiver 2700 adapted to transmit and receivesignaling over a telecommunications network. The transceiver 2700 may beinstalled in a host device. As shown, the transceiver 2700 comprises anetwork-side interface 2702, a coupler 2704, a transmitter 2706, areceiver 2708, a signal processor 2710, and a device-side interface2712. The network-side interface 2702 may include any component orcollection of components adapted to transmit or receive signaling over awireless or wireline telecommunications network. The coupler 2704 mayinclude any component or collection of components adapted to facilitatebi-directional communication over the network-side interface 2702. Thetransmitter 2706 may include any component or collection of components(e.g., up-converter, power amplifier, etc.) adapted to convert abaseband signal into a modulated carrier signal suitable fortransmission over the network-side interface 2702. The receiver 2708 mayinclude any component or collection of components (e.g., down-converter,low noise amplifier, etc.) adapted to convert a carrier signal receivedover the network-side interface 2702 into a baseband signal. The signalprocessor 2710 may include any component or collection of componentsadapted to convert a baseband signal into a data signal suitable forcommunication over the device-side interface(s) 2712, or vice-versa. Thedevice-side interface(s) 2712 may include any component or collection ofcomponents adapted to communicate data-signals between the signalprocessor 2710 and components within the host device (e.g., theprocessing system 2600, local area network (LAN) ports, etc.).

The transceiver 2700 may transmit and receive signaling over any type ofcommunications medium. In some embodiments, the transceiver 2700transmits and receives signaling over a wireless medium. For example,the transceiver 2700 may be a wireless transceiver adapted tocommunicate in accordance with a wireless telecommunications protocol,such as a cellular protocol (e.g., long-term evolution (LTE), etc.), awireless local area network (WLAN) protocol (e.g., Wi-Fi, etc.), or anyother type of wireless protocol (e.g., Bluetooth, near fieldcommunication (NFC), etc.). In such embodiments, the network-sideinterface 2702 comprises one or more antenna/radiating elements. Forexample, the network-side interface 2702 may include a single antenna,multiple separate antennas, or a multi-antenna array configured formulti-layer communication, e.g., single input multiple output (SIMO),multiple input single output (MISO), multiple input multiple output(MIMO), etc. In other embodiments, the transceiver 2700 transmits andreceives signaling over a wireline medium, e.g., twisted-pair cable,coaxial cable, optical fiber, etc. Specific processing systems and/ortransceivers may utilize all of the components shown, or only a subsetof the components, and levels of integration may vary from device todevice.

Although the description has been described in detail, it should beunderstood that various changes, substitutions and alterations can bemade without departing from the spirit and scope of this disclosure asdefined by the appended claims. Moreover, the scope of the disclosure isnot intended to be limited to the particular embodiments describedherein, as one of ordinary skill in the art will readily appreciate fromthis disclosure that processes, machines, manufacture, compositions ofmatter, means, methods, or steps, presently existing or later to bedeveloped, may perform substantially the same function or achievesubstantially the same result as the corresponding embodiments describedherein. Accordingly, the appended claims are intended to include withintheir scope such processes, machines, manufacture, compositions ofmatter, means, methods, or steps.

1. A method comprising: receiving a wireless packet in a 60 GHzfrequency band comprising a short training field (STF); determining afirst quantity of cross-correlation peaks between the STF and a firstpreamble component sequence, and a second quantity of cross-correlationpeaks between the STF and a second preamble component sequence, thefirst quantity being a first threshold or the second quantity being asecond threshold for a first packet type, the first quantity being thesecond threshold or the second quantity being the first threshold for asecond packet type; and determining that the wireless packet is thesecond packet type when the first quantity of cross-correlation peaksequals the second threshold or the second quantity of cross-correlationpeaks equals the first threshold.
 2. The method of claim 1, wherein thefirst threshold is forty-eight and the second threshold is sixteen. 3.The method of claim 1, wherein the first packet type is an Institute ofElectrical and Electronics Engineers (IEEE) 802.11ad packet type, andthe second packet type is an IEEE 802.11ay packet type.
 4. The method ofclaim 1, wherein the first preamble component sequence is Ga₁₂₈ and thesecond preamble component sequence is Gb₁₂₈.
 5. A method comprising:transmitting in a 60 GHz frequency band a wireless packet comprising ashort training field (STF), a header, a payload, and a training field,the STF producing a first quantity of cross-correlation peaks whencorrelated with a first preamble component sequence, the STF producing asecond quantity of cross-correlation peaks when correlated with a secondpreamble component sequence, the first quantity being a first thresholdor the second quantity being a second threshold for a first packet type,the first quantity being the second threshold or the second quantitybeing the first threshold for a second packet type.
 6. The method ofclaim 5, wherein the first threshold is forty-eight and the secondthreshold is sixteen.
 7. The method of claim 5, wherein the first packettype is an Institute of Electrical and Electronics Engineers (IEEE)802.11ad packet type, and the second packet type is an IEEE 802.11aypacket type.
 8. The method of claim 5, wherein the first preamblecomponent sequence is Gb₁₂₈ and the second preamble component sequenceis Ga₁₂₈.
 9. A method comprising: receiving a wireless packet in a 60GHz frequency band comprising a short training field (STF); determininga first quantity of cross-correlation peaks between the STF and a firstpreamble component sequence, and a second quantity of cross-correlationpeaks between the STF and a second preamble component sequence, thefirst quantity being a first threshold or the second quantity being asecond threshold for a first packet type; removing a phase shift fromthe STF to produce a phase shifted STF; determining a third quantity ofcross-correlation peaks between the phase shifted STF and the firstpreamble component sequence, and a fourth quantity of cross-correlationpeaks between the phase shifted STF and the second preamble componentsequence; and determining that the wireless packet is a second packettype when the third quantity equals the first threshold or the fourthquantity equals the second threshold.
 10. The method of claim 9, whereinthe first packet type is an Institute of Electrical and ElectronicsEngineers (IEEE) 802.11ad packet type, and the second packet type is anIEEE 802.11ay packet type.
 11. The method of claim 9, wherein removingthe phase shift from the STF comprises applying a linear phase rotationother than $^{j\; \pi \frac{n}{2}}$ to the STF.
 12. The method ofclaim 9, wherein removing the phase shift from the STF comprisesapplying a block rotation to the STF.
 13. A method comprising: adding aphase shift to a short training field (STF) to produce a phase shiftedSTF; and transmitting in a 60 GHz frequency band a wireless packetcomprising the phase shifted STF, a header, a payload, and a trainingfield, the phase shifted STF producing a first quantity ofcross-correlation peaks when correlated with a first preamble componentsequence and a second quantity of cross-correlation peaks whencorrelated with a second preamble component sequence, the phase shiftedSTF producing a third quantity of cross-correlation peaks whencorrelated with the first preamble component sequence and a fourthquantity of cross-correlation peaks when correlated with the secondpreamble component sequence after the phase shift is removed from thephase shifted STF, the first quantity being a first threshold or thesecond quantity being a second threshold for a first packet type, thethird quantity being the first threshold or the fourth quantity beingthe second threshold for a second packet type.
 14. The method of claim13, wherein the first packet type is an Institute of Electrical andElectronics Engineers (IEEE) 802.11ad packet type, and the second packettype is an IEEE 802.11ay packet type.
 15. The method of claim 13,wherein adding the phase shift to the STF comprises applying a linearphase rotation other than $^{j\; \pi \frac{n}{2}}$ to the STF. 16.The method of claim 13, wherein adding the phase shift to the STFcomprises applying a block rotation to the STF.
 17. A method comprising:receiving a wireless packet comprising a short training field (STF);determining cross-correlations between the STF and a first preamblecomponent sequence from a first set of preamble component sequencesassociated with a first packet type and between the STF and a secondpreamble component sequence from a second set of preamble componentsequences associated with a second packet type, the first preamblecomponent sequence and the second preamble component sequence having azero correlation zone (ZCZ) property; and determining that the wirelesspacket is the second packet type when there is a greater correlationbetween the STF and the second preamble component sequence than betweenthe STF and the first preamble component sequence.
 18. The method ofclaim 17, wherein the first packet type is an Institute of Electricaland Electronics Engineers (IEEE) 802.11ad packet type, and the secondpacket type is an IEEE 802.11ay packet type.
 19. The method of claim 17,wherein the ZCZ property is a ZCZ of at least 64 symbol time slots inwidth.
 20. The method of claim 17, wherein the first set of preamblecomponent sequences comprise preamble component sequences Ga₁₂₈ andGb₁₂₈.
 21. The method of claim 17, wherein the second set of preamblecomponent sequences comprise preamble component sequences Ga_(128,new,1)and Gb_(128,new,1).
 22. The method of claim 17, wherein the second setof preamble component sequences comprise mutual ZCZ sequences.
 23. Themethod of claim 22, wherein the mutual ZCZ sequences comprise preamblecomponent sequences Ga_(128,new,2) and Gb_(128,new,2).
 24. The method ofclaim 17, wherein the second set of preamble component sequencescomprise quadrature phase shift keying (QPSK) modulated preamblecomponent sequences.
 25. The method of claim 24, wherein the QPSKmodulated preamble component sequences comprise preamble componentsequences A₁₂₈ and B₁₂₈. 26.-36. (canceled)